As said by Trotter, everything sounds good.
You actually picked the mobo that I normailly recommend. I own the GA-K8NS Ultra, myself. I have determined it to be a wicked-awesome mobo.
WHen deciding on RAM, make sure to read my RAM guide, which I believe is at the top of this forum.
As for a PSU, 350W should be plenty.
Intel E6750...........PSN: ELBATROP
XFX nForce 650i Ultra
Patriot PC2-6400 8GB (4x2GB)
36GB WD Raptor
Samsung SyncMaster 931c
Samsung SyncMaster 750s
Windows 7 Home Premium 64